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Subject: Re: Frtiz8 performance depends upon version number

Author: Mike S.

Date: 16:33:16 12/25/02

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On December 25, 2002 at 18:12:58, Bob Durrett wrote:

>(...)
>The problem is that I am selecting moves different from the ones selected by
>Fritz 8 and then forcing Fritz 8 to analyze my moves.  I am merely a chess
>amateur.  Why are my moves often better than the ones Fritz 8 selects?  This
>should not happen more than once in a million moves.  But it is happening maybe
>once in ten moves.  I really don't understand this!!!!

This sound like an effect of different calculation times and/or hash size (or
even CPU speed) used in your analysis, compared to the games Fritz 8 played.

I assume you analyse games Fritz 8 has played, enter a different move
(variation) and the compare the evaluations of the original Fritz 8 with the one
of your new move?

In this case, you compare evals of *before* the move was actually played in the
game, with evals after the (alternative) move was entered, IOW one ply later.
When the original move is from short calculation time, I think it's not too
unusual that Fritz 8 comes to a better evaluation quickly (it would probably
come to a better evaluation if you point it to the position *after it's original
move* too). When the moves really are good and Fritz has the advantage, then the
tendency is that the advantage will increase, so if you analyse one ply later it
may search one ply further ahead...

You can also cross-check with another engine, to see if you notice the same
effect in general. I guess so. I guess also, that the positions you talk about,
are not sharp tactical one's? :o)

Regards,
M.Scheidl



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